1. Field of the Invention
The present invention relates to positioning and placing two types of articles that differ in size on a common support device.
2. Description of the Related Art
It is convenient if common support devices are usable for two types of articles that differ in size. For example, in a factory that deals with two types of semiconductor wafers that differ in size, two types of containers are used for the respective wafers, and therefore, it is convenient if these containers can be supported on the same support devices. These containers are provided with “V”-shaped grooves in a cross section at three positions in a bottom portion of the containers, and the containers are normally positioned by coupling three pins provided in the support device with the grooves. When these grooves are used to position the containers, only one type of the articles can be positioned. Therefore, two types of support devices are needed depending on the types of containers, resulting in inefficiency.
A related prior art will be shown. Patent Literature 1 (JP 2007-287877A) proposes a transport system for transporting two types of large and small articles where a container for the small article is accommodated in a container for the large article and they are transported.